Saramolee Prachid, Trubmusik Suchanat, Sunthondecha Thirayu, Nisoa Mudtorlep, Johns Jobish
School of Engineering and Technology, Walailak University, Nakhon Si Thammarat, 80160, Thailand.
Center of Excellence on Wood and Biomaterials, Walailak University, Nakhon Si Thammarat, 80160, Thailand.
Heliyon. 2021 Oct 1;7(10):e08120. doi: 10.1016/j.heliyon.2021.e08120. eCollection 2021 Oct.
Silica-filled natural rubber (NR) encounters incompatibility problems, owing to the strong particle-particle interaction arising from the hydrogen bonds of hydroxyl groups, which generally leads to the formation of agglomerates. The addition of coupling agents, especially silane coupling agents, reduces the agglomeration. However, this has some disadvantages, such as toxicity, a risk of pre-curing, and the generation of ethanol during mixing. This work aims to focus on the effect of filling the plasma-polymerisation of polyacetylene-coated silica into natural rubber compounds. The deposition of plasma-polymerised acetylene applied to silica particles was firstly carried out using a radio frequency (RF) with an input power of 20 kW for 60 min and further incorporated into NR compounds. On the surface of the coated silica analysis, the formation of a polyacetylene layer on the silica surface was obviously confirmed that it exhibited more stability in water. The following polyacetylene-coated silica (PA-coated silica)-filled NR compound properties were analysed: mixing energy and temperature, Payne effect, complex viscosity, and cure characteristics. The NR compounds mixed with PA-coated silica showed a lower mixing torque, dumping temperature, Payne effect, and viscosity, when compared to NR compounds with unmodified silica and ordinary silane systems. However, the differences were insignificantly noticed in the cure characteristics of the compounds. Polyacetylene-coated silica developed from plasma polymerisation can be used to improve the uniformity of dispersion, as well as the compatibility of silica in a natural-rubber matrix, without changing its cure characteristics, compared to the one with a silane coupling agent.
填充二氧化硅的天然橡胶（NR）存在不相容问题，这是由于羟基氢键产生的强烈颗粒间相互作用，通常会导致团聚体的形成。添加偶联剂，尤其是硅烷偶联剂，可以减少团聚现象。然而，这也存在一些缺点，如毒性、预固化风险以及混合过程中产生乙醇。这项工作旨在关注将聚乙炔包覆二氧化硅的等离子体聚合产物填充到天然橡胶胶料中的效果。首先使用输入功率为20千瓦的射频（RF）对二氧化硅颗粒进行60分钟的等离子体聚合乙炔沉积，然后将其进一步加入到NR胶料中。在对包覆二氧化硅的表面分析中，明显证实了二氧化硅表面形成了聚乙炔层，并且该聚乙炔层在水中表现出更高的稳定性。随后对填充聚乙炔包覆二氧化硅（PA包覆二氧化硅）的NR胶料性能进行了分析：混合能量和温度、佩恩效应、复数粘度和硫化特性。与填充未改性二氧化硅和普通硅烷体系的NR胶料相比，填充PA包覆二氧化硅的NR胶料显示出更低的混合扭矩、卸料温度、佩恩效应和粘度。然而，在胶料的硫化特性方面，差异并不显著。与使用硅烷偶联剂的情况相比，通过等离子体聚合制备的聚乙炔包覆二氧化硅可用于提高分散均匀性以及二氧化硅在天然橡胶基体中的相容性，同时不改变其硫化特性。
